title: Temperature induced-masculinisation in the Nile tilapia causes rapid up-regulation of both dmrt1 and amh expressions.
abstract: Nile tilapia has primarily a XX/XY sex determining system but minor genetic factors as well as temperature can override the major factors. Female XX progenies can be sex-reversed into functional males by rearing at high temperatures (>34°C) from 10dpf onwards. Temperature effects on the molecular pathways during sex differentiation in teleosts need to be deciphered. The temporal expression profiles of cyp19a1a and foxl2, two ovarian-developmental genes and dmrt1 and amh, two testes-developmental genes were analysed during key stages of the sex differentiation of genetic all-females, all-males and temperature-masculinised XX females (TM) tilapia. Overall QPCR analysis was similar between gonads and trunks. Both amh and dmrt1 expressions were up-regulated simultaneously in TM already at 13-15dpf. Dmrt1 expression became markedly elevated ∼3-fold higher than XY male levels at 20-26dpf whereas amh had similar levels to XY males. Foxl2 and cyp19a1a expression profiles were similar. Both were up-regulated at early stages in TM but repressed after 17-19dpf, whilest levels continued to increase in XX-females. Our results show that temperature action on tilapia testis development induces the rapid increase of both dmrt1 and amh expressions followed by the down-regulation of foxl2 and cyp19a1a. This suggests that dmrt1 and/or amh may be the modulator(s) of the down-regulation of foxl2 and/or cyp19a1a.
authors.affiliation: UMR Intrepid, CIRAD-PERSYST, Campus International de Baillarguet, 34398 Montpellier cedex 5, France.
authors.forename: Srisupaph
authors.initials: S
authors.lastname: Poonlaphdecha
authors.forename: Elodie
authors.initials: E
authors.lastname: Pepey
authors.forename: Marc
authors.initials: M
authors.lastname: Canonne
authors.forename: Hugues
authors.initials: H
authors.lastname: de Verdal
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Baroiller
authors.forename: Helena
authors.initials: H
authors.lastname: D'Cotta
mesh_terms: D000818:Animals; D023681:Cichlids / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006066:Gonads / Q000166:cytology / Q000378:metabolism; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D012733:Sex Differentiation / Q000235:genetics / Q000502:physiology; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics; D015854:Up-Regulation
chemical_list: C110547:DMRT1 protein; D014157:Transcription Factors
keywords: Fish; Gene regulation; Gonad; Sex differentiation; Temperature-induced masculinisation